Eyelet machine



w. D. PIERSON EYELET MACHINE Filed June 9. 1938 March 10, 1942.

5 Sheets-Sheet l INVENTOR mlliam Diiersou ATTO R N EY w. D. PIERSON 3 Sheets-Sheet 2 INVENTO ATTORNEY March 10, 1942. w, PIERSON 2,275,681

EYELET MACHINE Filed June 9, 195a s Sheets-Sheet 5 INVENTOR MllLzmDPlerson ATTORNEY Patented Mar. 10, 1942 EYELET MACHINE William D. Pierson, Watcrbury,,Conn., assignor to The Waterbury Farrel Foundry & Machine Company, Waterbury, Conn, a corporation of Connecticut Application June 9, 1938, Serial No. 212,830

2 Claims.

This: invention relates to cam-operated plunger presses, and more particularly to improvements in the plunger operating mechanism of an eyelet machine.

The invention is particularly adapted for use with multiple plunger presses wherein each of the plungers are driven in both directions by a pair of rotatable cams mounted on a common camshaft.

It has been the usual practice in cam-operated plunger presses of the above nature to employ hardened steel bumpers upon the upper ends of the plungers to be engaged by push-down cams, which plungers are usually constructed of two parts the upper or bumper part of which telescopes into the lower and is axially adjustable relatively to the lower part by means of a wedge. It has been found that the upper plunger part, when adjusted upwardly with respectto the lower part has a tendency to bend laterally, become distorted, or even to break at thepoint where it extends out of the lower part under the repeated stresses set up by the action of the driving cam upon its upper end, and especially when the punch is acting upon heavy material. Such bending or distortion may result in misalinement and cramping of the operating parts of the press.- Moreover, considerable wear always occurs between the cams and the bumpers, necessitating expensive and time-consuming repairs andjreplacement of parts.

By means of the present invention, the above and otherdisadvantages have been overcome.

One object of this invention is to substitute for each of the bumpers mentioned above a removable hardened roller, which is carried by the upper end of each plunger for engagement with the downwardly driving cams.

Another object is to provide vertical guiding means for the holders ofsaid rollers in order to retain said rollers accurately in operating position relatively to driving cams engaged thereby at allpositions of their adjustment with respect to the lower plunger part.

Another object is toadapt and arrange such roll-er guiding means so that the upper part of the plunger will be rigidlysupported even when it is extended out of the lower part and will strongly resist any tendency for lateral bending or distortion of said plungers.

, A still further object is to provide a machine of the, above nature which will be relatively simple, in construction, inexpensive to manufacture, readily manipulated, easy to repair and make replacement of parts, compact, and very efficient and durable in use.

With these and other objects in View there have been illustrated in the accompanying drawings two forms in whichthe invention may be conveniently embodied in practice.

In the drawings:

Fig.1 is a partial front View of an eyelet machine embodying the features and principles of this invention.

Fig. 2 is a vertical sectional View of the same, taken along the line 2-2 of Fig. 1, and showing a side view of one set of cams, a plunger, and a lifting rod.

Fig. 3 is an enlarged top planview of a roller, a holder, and the kneepiece for guiding said holder.

Fig. 4 is a fragmentary vertical sectional view, taken along the line 44 of Fig. 3.

Fig. 5 is a fragmentary side elevational view of the parts shown in Fig. 4, as they appear in a different position of adjustment.

Fig. 6 is a sectional View. of one of the plungers, showing the wedge for axially adjusting the relative positions of the upper and lower parts of said plunger.

Fig. 7 is a sectional view of one of the plungers, taken on the line 1-1 of Fig. 2.

Fig. 8 is a vertical sectional view of a modified form of eyelet machine having a double lifter mechanism.

Fig. 9 is a sectional view of one of the plungers and thetwo lifting rods, taken on the line 99 of Fig. 8.

Referring now to the drawings, wherein like reference characters designate like parts throughout the several views, the numeral Ill designates a pair of upright side frames, only oneof which is shown, said side frames being connected by an upper horizontal top member II and a lower horizontal die bed [2, A die holding block I3 is seated on the diebed l2 and is suitably secured thereto, as by bolts (not shown) A hori- Zontal cam shaft l4 extends between the frames I 0, being suitably journaled therein, and said cam shaft is adapted to be rotatively driven by any suitable driving means, such as by a beltlfi connecting a power driven shaft (not shown) to a pulley l6 secured to the cam shaft M in the usual manner.

For cooperating with the dies (not shown), provision is made of a plurality of 'plungers, each comprising an upper part 21 and a lower part I1. The lower part I! of each plunger is squared in cross-section, hasa punch-carrying member l8 at its lower end, and is mounted to reciprocate in square holes formed partly in each of a pair of horizontal vertically spaced-apart frameportions l9 and 29, and partly in plunger caps 19a and 20a, said frame portions extending between the side frames I0, and said caps being secured to the respective frame portions by screw bolts 2 la. y

A plurality of strippers 2| (see Figs. 1 and 2) are rigidly secured to the lower frame portion 20 just below the punch carrying members I8. Each lowerv plunger part l1 has a cylindrical bore 22 extending downwardly from its upper end for about half of its length. An elongated transverse wedge opening 23 extends through the lower plunger part I1 at the bottom of the bore 22 and said lower plunger part is provided with a reduced groove 24 adjacent its upper end, which groove forms a cylindrical neck 25 spaced from the upper end by a squared portion 26.

The upper plunger section 21 is preferably made in the form of a rectangular block and has a cylindrical rod 28 depending therefrom and adapted to be telescopically received within the bore 22 of the lower plunger part 11.

In order to obtain any desired vertical adjust- I ment of the upper plunger part 21 relative to the lower plunger part l1, provision is made of a Wedge block 29 which is inserted in the cross opening 23 with its inclined edge 39 in engagement with an inclined end surface 31 formed on the lower end of the depending rod 28. The Wedge block 29 is adapted to be locked in adjusted position by means of a transverse set screw 32 which extends through one wall of the lower plunger part [1 and engages one side of the wedge block 29.

The block of the upper plunger section'21 is provided with an upwardly open semi-cylindrical recess 33 adapted to receive a cylindrical roller 34 mounted to rotate'in an anti-friction bearing-preferably of the standard roller bearing type, as shownthe spindle 35a of which is provided on its opposite ends with square trunnions 35 and 36 adapted to be seated in flat sided slots 31 and 38, respectively, formed in opposite sides of said block 21. The slots 31 and 38 are open at the top to permit the trunnions 35 and 35 and roller 34 to be readily inserted and removed. The roller bearing roller 34 is secured to the top plunger block 21 by means of a cotter pin 21a which passes through the trunnion 35 and the sides of the block 21 adjacent thereto.

The horizontal axis of the roller spindle 34a is arranged vertically below the axis of the cam shaft 14, whereby the roller 34 will be in position to be engaged by and to ride on the periphery of a plunger driving cam 39 secured to said shaft M, as by a key 40.

An upward pushing lifting cam ll is secured to the cam shaft 14, as by a key 42, and said lifting cam M engages a hardened lifter arm 43 having a rear enlarged split body portion 44 which encircles a vertically disposed lifter rod 45, to which it is clamped, as by a bolt 45. The lifter rod 45 is journaled to reciprocate up and down in suitable bearing bushings 41, 48 and 49, respectively, disposed in the upper horizontal frame member H, and the frame portions I9 and 20.

In order to frictionally support the upper end of the lifter rod 45 in elevated position at the end of its upward stroke, provision is made of a spring clamping device 59 secured. to the upper frame member I I by a screw 5|,

A horizontal kneepiece 52 encircles the lifter rod 45 and is secured thereto by a tapered pin 53, said kneepiece being enlarged at the forward end to form a semi-circular section fitting about one side of the cylindrical neck portion 25 of the lower plunger part 11. A detachable cap member 54, also having a semi-circular section shaped to fit about the cylindrical neck portion 25, is secured to the forward end of the kneepiece 52 by screws 55.

In order to form supports for the top block of the upper plunger part 21, the kneepiece 52 and the cap 54 are both provided with upstanding lugs 56 and 51, respectively. The lugs 56 and 51 are machined flat on their inner opposing surfaces to form parallel faces 58 and 59, respectively, for engaging the flat opposite end surfaces 69 and 8| of the plunger block 21. The block is clamped securely in position by means of a set screw 62 passing through the lug 51 and having a lock nut 63 thereon. The set screw engages a friction pad 64, preferably made of copper or other relatively soft metal and presses it against the adjacent end surface of the upper plunger block.

In the modified form of the invention shown in Figs. 8 and 9, the mechanism is provided with a pair of lifter rods 10 and H, one on either side of the shaft M, said rods being joined together above a lifting cam 12 by a lifting cross bar 13. The cross bar 13 rides on the periphery of the cam 12 to lift the rods 19 and 1| simultaneously. The lifter rod 10 and 1! are mounted to reciprocate in bearings 14 and 15 provided in an upper frame member 15, and are guided on their outer sides by a pair of arcuate half bushing bearings 11 and 18, respectively. The bearings 11 and 18 are supported by brackets-19 and 89, respectively, which extend between side frames 8|, only one of which is shown.

In this modified form of double lifter eyelet machine, the anti-friction roller 82, which engages the periphery of a downwardly pushing driving cam 83, is secured in the top plunger block by a removable cotter pin 84, and said block is rigidly supported against lateral bending by means of the vertical opposing surfaces and 86 of a pair of upstanding lugs 81 and 88, respectively, mounted on a cross bar 89. The cross bar 89 is adapted to encircle half of the reduced cylindrical neck portion 25 of the plunger part 21 and cooperates with a side cap 90, formed to encircle the other half of the neck 25, said cap 99 being clamped to the cross bar 89 by screws 9| (see Fig. 9). The cross bar 89 is secured at its ends to the lifter rods 19 and 1| by nuts 92 and lock nuts 93.

It will be seen from the above that in both forms of the invention, the upper plunger part 21 is telescopically disposed in the bore of the lower plunger part 11 permitting said parts to be axially adjusted with respect to each other by means of the wedge block 29 for controlling the length of the two-part plunger.

One advantage of the present invention lies in the provision of the parallel guiding surfacefor the opposite sides of the block of the upper plunger part 21, thus rigidly supporting said block.

A further advantage is that the anti-friction roller may be readily and quickly removed from the upper plunger part 21 for replacement when required due to Wear or breakage, thus avoiding the expense of supplying an entirely new plunger. Another advantage of the form of machine shown in Figs. 1 and 2 is that the respective plungers may be readily and quickly removed from the front of the machine, due to the fact that the kneepiece cap 54 and the plunger caps 19a and 20a are disposed at the front of said plungers.

While the invention has been disclosed herein as exemplified in an eyelet machine, it will be understood that it may also beemployed in any other form of single or multiple plunger press within its general principles and scope.

While there have been disclosed in this specification two forms inwhich the invention may be embodied, it is to be understood that these forms are shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosures, butmay be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming withinthe scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired to secure Letters Patent, is

1. In a plunger press, a punch-carrying plunger having a cam-engaging roller bumper rotatablymounted in the upper end thereof for driving said plunger downwardly, a cam-operated kneepiece connected with the top of said plunger for driving the latter upwardly, said kneepiece comprising a body member for connection with a reciprocating lifter rod and a front cap member, each of said members partially embracing said plunger and having upstanding guide means engaging said plunger to prevent bending of the top thereof, and a clamping screw carried by said front cap member and having a friction pad on its end for engaging said plunger to prevent accidental jumping upward of said roller due to shocks.

2. In a plunger press, a punch-carrying plunger having a cam-actuated bumper-carrying member mounted to adjustably telescope in the upper part of said plunger for driving said plunger on the downward stroke of said punch, a camdriven lifter rod for driving said plunger on the upward stroke of said punch, a kneepiece carried by said lifter rod located at the top of said plunger, means on said kneepiece embracing the front and rear of the head of said bumper to prevent bending of the latter under the severe stresses of the plunger-actuating cam, and a pair of lower bearings for said plunger located below said kneepiece.

WILLIAM D. PIERSON. 

